A target assembly conventionally comprises a target holder, such as a plate or tube, carrying a layer of a target material applied to its outer surface.
Thermal spraying techniques are often employed to apply the target material onto the target holder. In some other cases, the metal target material is cast on a target holder.
Sprayed targets as for example zinc targets show the disadvantage of forming highly porous structures.
Zinc targets obtained by casting techniques are characterised by a somewhat higher density, but they have the disadvantage that the bonding between individual grains may be poor.